Flax-leaved St John's-wort

About: This fussy plant has very particular habitat requirements, explaining its rarity and limited range. It needs plenty of space with few other competitive plants nearby, and acidic soils in warm areas. Steep rocky slopes exposed to the sun are a favourite. Flowers between June and July.

How to identify: Look for reddish stems, and long, thin leaves that grow from opposite sides of the stalk. Flowers are yellow and delicately dotted at the edges with tiny black glands.

Where: Very rare and limited to south Devon, the west parts of Wales and the Channel Islands